Simplify ownership of a ThreadState's interruptors.

Source/platform/heap/ThreadState.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 427 matching lines @@
         // call onInterrupted on that thread once interruption
         // succeeds.
         virtual void requestInterrupt() = 0;
 
     protected:
         // This method is called on the interrupted thread to
         // create a safepoint for a GC.
         void onInterrupted();
     };
 
+    // addInterruptor() takes ownership of the registered interruptor.
     void addInterruptor(Interruptor*);
     void removeInterruptor(Interruptor*);
 
-    // Should only be called under protection of threadAttachMutex().
-    const Vector<Interruptor*>& interruptors() const { return m_interruptors; }
-
     void recordStackEnd(intptr_t* endOfStack)
     {
         m_endOfStack = endOfStack;
     }
 
     // Get one of the heap structures for this thread.
     // The thread heap is split into multiple heap parts based on object types
     // and object sizes.
     BaseHeap* heap(int heapIndex) const
     {
@@ skipping 246 matching lines @@
 
     void invokePreFinalizers();
 
     void takeSnapshot(SnapshotType);
 #if ENABLE(GC_PROFILING)
     void snapshotFreeList();
 #endif
     void clearHeapAges();
     int heapIndexOfVectorHeapLeastRecentlyExpanded(int beginHeapIndex, int endHeapIndex);
 
+    using InterruptorVector = Vector<OwnPtr<Interruptor>>;
+
+    // Should only be called under protection of threadAttachMutex().
+    const InterruptorVector& interruptors() const { return m_interruptors; }
+
     friend class SafePointAwareMutexLocker;
     friend class SafePointBarrier;
     friend class SafePointScope;
 
     static WTF::ThreadSpecific<ThreadState*>* s_threadSpecific;
     static uintptr_t s_mainThreadStackStart;
     static uintptr_t s_mainThreadUnderestimatedStackSize;
     static SafePointBarrier* s_safePointBarrier;
 
     // We can't create a static member of type ThreadState here
     // because it will introduce global constructor and destructor.
     // We would like to manage lifetime of the ThreadState attached
     // to the main thread explicitly instead and still use normal
     // constructor and destructor for the ThreadState class.
     // For this we reserve static storage for the main ThreadState
     // and lazily construct ThreadState in it using placement new.
     static uint8_t s_mainThreadStateStorage[];
 
     ThreadIdentifier m_thread;
     OwnPtr<PersistentRegion> m_persistentRegion;
     StackState m_stackState;
     intptr_t* m_startOfStack;
     intptr_t* m_endOfStack;
     void* m_safePointScopeMarker;
     Vector<Address> m_safePointStackCopy;
     bool m_atSafePoint;
-    Vector<Interruptor*> m_interruptors;
+    InterruptorVector m_interruptors;
     bool m_sweepForbidden;
     size_t m_noAllocationCount;
     size_t m_gcForbiddenCount;
     int m_persistentAllocated;
     int m_persistentFreed;
     BaseHeap* m_heaps[NumberOfHeaps];
 
     int m_vectorBackingHeapIndex;
     size_t m_heapAges[NumberOfHeaps];
     size_t m_currentHeapAges;
@@ skipping 43 matching lines @@
 };
 
 template<> class ThreadStateFor<AnyThread> {
 public:
     static ThreadState* state() { return ThreadState::current(); }
 };
 
 } // namespace blink
 
 #endif // ThreadState_h